Customer cannot receive email from certain domain
I've got an ongoing issue where one of our customers cannot receive any email from only ONE specific outside domain ...
Our customer is hosted on our main shared IP, which is the IP for hundreds of customers. Nobody complains, and my customer can get email from EVERYBODY ELSE.
However, when someone emails him from @unitedpower.com, it never gets to us . They are not blacklisted - actually, we whitelisted them just to be sure ... the mail never gets through.
The unitedpower.com firewall vendor INSISTS it's not their firewall, although the only way they ever see the error message is in their firewall - below is the errors in the firewall:
I have my firewall vendor take another look at the problem with your mail. Here is his response. Maybe it could be helpful to your mail support.
I am connected to your server now. I will try to capture the port 25 traffic to their mail server to see why the server refused the mail service. The mail admin for mail.spectrumeng.net[67.18.104.4 would be the best to ask why. I suspect it is because you can send a limited amount of emails to them
From the tcp dump I see found following:
421 F-03426. Maximum proxy clients (20) re
I am connected to your server now. I will try to capture the port 25 traffic to their mail server to see why the server refused the mail service. The mail admin for mail.spectrumeng.net[67.18.104.4 would be the best to ask why. I suspect it is because you can send a limited amount of emails to them
From the tcp dump I see found following:
421 F-03426. Maximum proxy clients (20) re
ANY CLUES???
Thanks,
Fred
